[SCSI] qla4xxx: Fix return code for qla4xxx_session_get_param.

While reading sysfs chap_in_idx and chap_out_idx attribute, if chap
authentication is not set we get an error as "Invalid argument".
Signed-off-by: Manish Rangankar <manish.rangankar@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla4xxx/ql4_os.c

@@ -1337,8 +1337,8 @@ static int qla4xxx_session_get_param(struct iscsi_cls_session *cls_sess,
 					      sess->password_in, BIDI_CHAP,
 					      &idx);
 		if (rval)
-			return -EINVAL;
-
+			len = sprintf(buf, "\n");
+		else
 			len = sprintf(buf, "%hu\n", idx);
 		break;
 	case ISCSI_PARAM_CHAP_OUT_IDX:
@@ -1346,8 +1346,8 @@ static int qla4xxx_session_get_param(struct iscsi_cls_session *cls_sess,
 					      sess->password, LOCAL_CHAP,
 					      &idx);
 		if (rval)
-			return -EINVAL;
-
+			len = sprintf(buf, "\n");
+		else
 			len = sprintf(buf, "%hu\n", idx);
 		break;
 	default: